1. Field of the Invention
The present invention relates to an Alpine ski boot of the rear entrance type comprising apparatus which compensates for the difference in variation of the angle of the leg of a skier with respect to the angle of the ski boot upper.
2. Description of Prior Art
Various types of ski boots are presently available in the market which are adapted to assure that a skier can control the direction of his skis by the use of certain techniques. So as to increase performance when using such techniques, modern ski boots extend to variable heights above the zone of the malleoli of the user to surround the entire base of the leg of the user. However, the materials utilized for forming such ski boots, such as relatively rigid plastic materials, do not allow the skier comfort when used. This is particularly true with ski boots having high uppers, whether or not the uppers are journalled on the shell base of the boot. In effect, to permit the skier to use them in various Alpine ski disciplines, i.e., in competition, along trails, and outside of trails, it is desirable to be able to vary the angle of frontward inclination of such boots. This front angle of inclination is relatively substantial, depending upon the anticipated use of the boot, such as in downhill racing or in off-trail skiing, for example. For this reason, prior art ski boots were made with their uppers journalled on the shell base such that the angle of frontward inclination of the uppers could be varied.
Such boots have been described in German Pat. No. 20 58 969 and in U.S. Pat. No. 3,619,914. However, even though such boots allow for variation of the angle of frontward inclination, they are in most cases uncomfortable with respect to the tibial support of the leg of the skier during frontward flexions of the leg, which are exerted in the course of skiing. This discomfort results precisely from the fact that the journal axis of the upper never corresponds, in practice, with the journal formed by the ankles of the user. This difference between the journal axis of the upper of the boot, and that of the skier, produces, during flexions of the leg of the skier in the boot, a linear contact zone completely around the tibial support area of the leg; this zone is caused by the angular differences between the bottom of the leg and the upper resulting from the lack of alignment of their respective journal axes.
Quite obviously, such disadvantages are even more evident with boots having uppers which are not journalled and in which the foot is inserted from the rear. Thus, manufacturers have attempted to increase the comfort of such boots by providing various apparatus, such as slits on the front of the upper whose spacing is controlled by a movable cursor along the length of these slits, as has been described in German Pat. No. 2,410,063. This type of apparatus does not overcome the problem of discomfort for the tibial support, but only serves to displace the contact zone, and hence the discomfort, as a function of the position of the movable cursor along the front of the upper.
The problem of the leg comfort of the skier is not limited only to frontward flexions, as has already been described in French Pat. No. 2,089,128, in which a pivotable apparatus is provided at the rear of a ski boot having a non-journalled upper such that the leg of the skier does not undergo linear contact, otherwise caused by contact between the upper edge of the upper in the rear frame of the boot and a rear portion of the leg of the skier which would be exerted during skiing. Such pivotable apparatus is designed only to protect the calf of the skier.